Method of manufacturing micro-LED array display devices with CMOS cells

ABSTRACT

Micro-LED array display devices are disclosed. One of the micro-LED display devices includes: a micro-LED panel including a plurality of micro-LED pixels; a CMOS backplane including a plurality of CMOS cells corresponding to the micro-LED pixels to individually drive the micro-LED pixels; and bumps electrically connecting the micro-LED pixels to the corresponding CMOS cells in a state in which the micro-LED pixels are arranged to face the CMOS cells. The micro-LED pixels are flip-chip bonded to the corresponding CMOS cells formed on the CMOS backplane through the bumps so that the micro-LED pixels are individually controlled.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.15/613,233, filed Jun. 4, 2017, which claims the benefit of KoreanPatent Application No. 10-2016-0090600, filed Jul. 18, 2016. Thecontents of these applications are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to micro-LED array display devices, andmore specifically to micro-LED array display devices in which aplurality of micro-LED pixels are arrayed on one micro-LED panel byetching for the production of LED chips and the pixel-arrayed micro-LEDpanel is flip-chip bonded to a CMOS backplane through bumps so that themicro-LED pixels can be individually driven, thus being suitable formicrodisplay applications.

BACKGROUND

Demand for light emitting diodes (LEDs) has expanded exponentially interms of low power consumption and environmental friendliness. LEDs areused as backlights for lighting apparatuses and LCD devices and arewidely applied to display devices.

LEDs are kinds of solid-state elements that convert electrical energyinto light. LEDs are based on the principle that when a voltage isapplied between two doped layers, i.e. an n-type semiconductor layer anda p-type semiconductor layer, between which an active layer isinterposed, electrons and holes are injected into and recombine in theactive layer to emit light. LEDs can be driven at relatively low voltageand have high energy efficiency. Due to these advantages, LEDs release asmall amount of heat. LEDs can be produced in various types.Particularly, micro-LED array display devices are fabricated based ontypes of LEDs in which a plurality of micro-LED pixels are formed on onewafer. According to a conventional method for the fabrication of amicro-LED array display device in which a plurality of micro-LED pixelsare formed on one wafer, a p-type terminal and an n-type terminal areformed in each pixel through a chip production process and are arrayedalong the longitudinal and transverse axes of signal lines to drive thepixel. In this case, elements responsible for signal control in themicro-LED pixels should be disposed in the vicinity of the micro-LEDpixels, resulting in an increase in the size of the micro-LED arraydisplay device. Further, data lines arrayed along the longitudinal andtransverse axes should be connected to the micro-LED pixels by wirebonding, making the process complicated and inconvenient.

The formation of a plurality of micro-LED pixels on one substratetechnically limits the production of structures emitting red, green, andblue light. Because of this technical difficulty, the use of LEDs aslight sources in micro-LED array display devices inevitably leads to theemission of monochromatic light. Thus, there is a need in the art for anapproach that can provide a solution to the problems of the prior art.

SUMMARY

One object of the present invention is to provide a micro-LED arraydisplay device in which micro-LED pixels are flip-chip bonded tocorresponding CMOS cells formed on a CMOS backplane through bumps, thusavoiding the complexity and inconvenience of wire bonding for connectingmicro-LED pixels to various data lines while enabling individual controlof the micro-LED pixels.

A further object of the present invention is to provide a micro-LEDarray display device in which micro-LED panels, each including aplurality of micro-LED pixels, are flip-chip bonded to a single CMOSbackplane, thus overcoming the difficulties of the prior art in formingred, green, and blue light emitting structures including micro-LEDpixels formed on one substrate.

According to one aspect of the present invention, there is provided amicro-LED array display device including: a micro-LED panel including aplurality of micro-LED pixels; a CMOS backplane including a plurality ofCMOS cells corresponding to the micro-LED pixels to individually drivethe micro-LED pixels; and bumps electrically connecting the micro-LEDpixels to the corresponding CMOS cells in a state in which the micro-LEDpixels are arranged to face the CMOS cells, wherein the micro-LED pixelsare flip-chip bonded to the corresponding CMOS cells formed on the CMOSbackplane through the bumps so that the micro-LED pixels areindividually controlled.

According to one embodiment, the micro-LED pixels are formed by growinga first conductivity-type semiconductor layer, an active layer, and asecond conductivity-type semiconductor layer in this order on asubstrate and etching the layers, the micro-LED pixels have a verticalstructure including the first conductivity-type semiconductor layer, theactive layer, and the second conductivity-type semiconductor layerformed in this order, and the active layer and the secondconductivity-type semiconductor layer are removed from the exposedportions of the first conductivity-type semiconductor layer where noneof the micro-LED pixels are formed.

According to one embodiment, a first conductivity-type metal layer isformed over the portions of the first conductivity-type semiconductorlayer where none of the micro-LED pixels are formed and is spaced apartfrom the micro-LED pixels.

According to one embodiment, the first conductivity-type metal layer isformed along the periphery of the micro-LED panel on the firstconductivity-type semiconductor layer.

According to one embodiment, the first conductivity-type metal layer hasthe same height as the micro-LED pixels.

According to one embodiment, the first conductivity-type metal layerfunctions as a common electrode of the micro-LED pixels.

According to one embodiment, the CMOS backplane includes a common cellformed at a position corresponding to the first conductivity-type metallayer and the first conductivity-type metal layer is electricallyconnected to the common cell through a common bump.

According to one embodiment, the first conductivity-type is n-type andthe second conductivity-type is p-type.

According to one embodiment, the substrate is made of a materialselected from sapphire, SiC, Si, glass, and ZnO.

According to one embodiment, the bumps are formed on the CMOS cells andare melted by heating such that the CMOS cells are electricallyconnected to the corresponding micro-LED pixels.

According to a further aspect of the present invention, there isprovided a micro-LED array display device including: first, second, andthird micro-LED panels emitting light of different wavelength bands,each of the micro-LED panels including a plurality of micro-LED pixels;a single CMOS backplane including a plurality of CMOS cellscorresponding to the micro-LED pixels of the first, second, and thirdmicro-LED panels to individually drive the micro-LED pixels; and bumpselectrically connecting the micro-LED pixels of the first, second, andthird micro-LED panels to the corresponding CMOS cells in a state inwhich the micro-LED pixels of the first, second, and third micro-LEDpanels are arranged to face the CMOS cells, wherein the micro-LED pixelsof the first, second, and third micro-LED panels are flip-chip bonded tothe corresponding CMOS cells formed on the CMOS backplane through thebumps so that the micro-LED pixels are individually controlled.

In the new concept of micro-LED array display device according to thepresent invention, micro-LED pixels are flip-chip bonded to micro-LEDpixels formed on a CMOS backplane through bumps, avoiding the complexityand inconvenience of wire bonding for connecting micro-LED pixels tovarious data lines while enabling individual control of the micro-LEDpixels. The micro-LED array display device of the present invention inwhich a plurality of micro-LED panels emitting red, green, and bluelight are flip-chip bonded to a single CMOS backplane through bumps canfocus three colors on the same area using an optical system to achievefull color. Therefore, the micro-LED array display device of the presentinvention is effective in overcoming the technical difficulties of theprior art in forming red, green, and blue light emitting structuresincluding a plurality of micro-LED pixels on one substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 illustrates an exemplary micro-LED panel 100 of a micro-LED arraydisplay device according to one embodiment of the present invention;

FIG. 2 illustrates the micro-LED panel 100 of FIG. 1 including micro-LEDpixels and a CMOS backplane 200 including a plurality of CMOS cellsadapted to individually drive the micro-LED pixels of the micro-LEDpanel 100;

FIG. 3 illustrates a state in which the micro-LED panel 100 and the CMOSbackplane 200 illustrated in FIG. 2 are electrically connected to eachother through bumps 300 arranged on the CMOS backplane 200;

FIG. 4 illustrates a state in which the micro-LED panel 100 and the CMOSbackplane 200 illustrated in FIG. 3 are arranged to face each otherthrough the bumps 300 to electrically connect the micro-LED pixels ofthe micro-LED panel 100 to the CMOS cells of the CMOS backplane 200;

FIG. 5 illustrates a state in which red, green, and blue micro-LEDpanels 1100, 1200, and 1300, a single CMOS backplane 2000 having CMOScell areas 2100, 2200, and 2300 where the micro-LED panels 1100, 1200,and 1300 are to be electrically connected to CMOS cells, and bumps 3000arranged on the CMOS cells to achieve full color in a micro-LED arraydisplay device according to one embodiment of the present invention;

FIG. 6 illustrates a state in which the red, green, and blue micro-LEDpanels 1100, 1200, and 1300 are electrically connected to the singleCMOS backplane 2000 through the bumps 3000 in the micro-LED arraydisplay device of FIG. 5; and

FIG. 7 is a view for briefly explaining the driving of the micro-LEDarray display device illustrated in FIG. 5 to achieve full color.

DETAILED DESCRIPTION

The present invention is directed to a micro-LED array display device inwhich micro-LED pixels are arrayed by MESA etching and are flip-chipbonded to a CMOS backplane, thus being applicable to a micro display,such as a head mounted display (HMD) or head up display (HUD). In themicro-LED array display device of the present invention, micro-LEDpixels arrayed by MESA etching for the production of LED chips areflip-chip bonded to a CMOS backplane so that they can be individuallydriven. The present invention is also directed to a micro-LED arraydisplay device in which three red, green, and blue light emittingelements, i.e. micro-LED panels, are arrayed on a CMOS backplane toachieve full color.

Preferred embodiments of the present invention will now be describedwith reference to the accompanying drawings. The drawings andembodiments described with reference to the drawings are simplified andillustrated such that those skilled in the art can readily understandthe present invention. Accordingly, the drawings and the embodimentsshould not be construed as limiting the scope of the present invention.

FIG. 1 illustrates an exemplary micro-LED panel 100 of a micro-LED arraydisplay device according to one embodiment of the present invention,FIG. 2 illustrates the micro-LED panel 100 including micro-LED pixelsand a CMOS backplane 200 including a plurality of CMOS cells adapted toindividually drive the micro-LED pixels of the micro-LED panel 100, FIG.3 illustrates a state in which the micro-LED panel 100 and the CMOSbackplane 200 are electrically connected to each other through bumps 300arranged on the CMOS backplane 200, and FIG. 4 illustrates a state inwhich the micro-LED panel 100 and the CMOS backplane 200 are arranged toface each other through the bumps 300 to electrically connect themicro-LED pixels of the micro-LED panel 100 to the CMOS cells of theCMOS backplane 200.

Referring first to FIGS. 1 to 4, a description will be given of amicro-LED array display device according to one embodiment of thepresent invention. The micro-LED array display device includes amicro-LED panel 100, a CMOS backplane 200, and bumps 300. The micro-LEDpanel 100 includes a plurality of micro-LED pixels 130. The CMOSbackplane 200 includes a plurality of CMOS cells 230 corresponding tothe micro-LED pixels 130 to individually drive the micro-LED pixels 130.The micro-LED pixels 130 are electrically connected to the correspondingCMOS cells 230 through the bumps 300 in a state in which the micro-LEDpixels 130 are arranged to face the CMOS cells 230. In FIGS. 1 to 4,only one of the micro-LED pixels and only one of the CMOS cells aredenoted by reference numerals 130 and 230, respectively, for the purposeof convenience. The micro-LED pixels 130 are flip-chip bonded to thecorresponding CMOS cells 230 formed on the CMOS backplane 200 throughthe bumps 300. Due to this construction, the micro-LED pixels 130 can beindividually controlled.

The micro-LED pixels 130 of the micro-LED panel 100 are formed bygrowing a first conductivity-type semiconductor layer 132, an activelayer 134, and a second conductivity-type semiconductor layer 136 inthis order on a substrate 110 and etching the layers. The micro-LEDpixels have a vertical structure including the first conductivity-typesemiconductor layer 132, the active layer 134, and the secondconductivity-type semiconductor layer 136 formed in this order on thesubstrate 110. The substrate 110 may be made of a material selected fromsapphire, SiC, Si, glass, and ZnO. The first conductivity-typesemiconductor layer 132 may be an n-type semiconductor layer and thesecond conductivity-type semiconductor layer 136 may be a p-typesemiconductor layer. The active layer 134 is a region where electronsfrom the first conductivity-type semiconductor layer 132 recombine withholes from the second conductivity-type semiconductor layer 136 whenpower is applied.

The second conductivity-type semiconductor layer 136 and the activelayer 134 are removed from the etched portions 120 of the micro-LEDpanel 100 where none of the micro-LED pixels 130 are formed, and as aresult, the first conductivity-type semiconductor layer is exposed inthe etched portions. The micro-LED panel 100 includes a firstconductivity-type metal layer 140 formed over the portions 120 of thefirst conductivity-type semiconductor layer 132 where none of themicro-LED pixels 130 are formed. The first conductivity-type metal layer140 is spaced apart from the micro-LED pixels 130. The firstconductivity-type metal layer 140 is formed with a predetermined widthalong the periphery of the micro-LED panel 100 on the firstconductivity-type semiconductor layer 132. The first conductivity-typemetal layer 140 has substantially the same height as the micro-LEDpixels 130. The first conductivity-type metal layer 140 is electricallyconnected to the CMOS backplane 200 through the bumps 300. As a result,the first conductivity-type metal layer 140 functions as a commonelectrode of the micro-LED pixels 130. For example, the firstconductivity-type metal layer 140 may be a common ground.

The plurality of CMOS cells 230 of the CMOS backplane 200 serve toindividually drive the micro-LED pixels 130. The CMOS cells 230 areelectrically connected to the corresponding micro-LED pixels throughbumps 330. The CMOS cells 230 are integrated circuits for individuallydriving the corresponding micro-LED pixels. The CMOS backplane 200 maybe, for example, an active matrix (AM) panel. Specifically, each of theCMOS cells 230 may be a pixel driving circuit including two transistorsand one capacitor. When the micro-LED panel 100 is flip-chip bonded tothe CMOS backplane 200 through the bumps 300, each of the micro-LEDpixels may be arranged between a drain terminal and a common groundterminal (e.g., reference numeral 240) of a transistor of the pixeldriving circuit to form an equivalent circuit.

The CMOS backplane 200 includes a common cell 240 formed at a positioncorresponding to the first conductivity-type metal layer 140. The firstconductivity-type metal layer 140 is electrically connected to thecommon cell 240 through a common bump 340. Herein, the bumps 300 isoften intended to include the bumps 330 electrically connecting theplurality of CMOS cells to the micro-LED pixels and the common bump 340electrically connecting the first conductivity-type metal layer 140 tothe common cell 240.

As illustrated in FIG. 3, the CMOS backplane 200 on which the CMOS cells230 are arranged faces the micro-LED panel 100. After the CMOS cells 230are brought into contact with the micro-LED pixels 130 in a one-to-onerelationship, the bumps 330 and the common bump 340 are melted byheating. As a result, the CMOS cells 230 are electrically connected tothe corresponding micro-LED pixels 130, as illustrated in FIG. 4.

Referring next to FIGS. 5 and 6, a description will be given of amicro-LED array display device capable of achieving full color accordingto a further embodiment of the present invention. FIG. 5 illustrates astate in which red, green, and blue micro-LED panels 1100, 1200, and1300, a single CMOS backplane 2000 having CMOS cell areas 2100, 2200,and 2300 where the micro-LED panels 1100, 1200, and 1300 are to beelectrically connected to CMOS cells, and bumps 3000 arranged on theCMOS cells to achieve full color in a micro-LED array display deviceaccording to one embodiment of the present invention and FIG. 6illustrates a state in which the red, green, and blue micro-LED panels1100, 1200, and 1300 are electrically connected to the single CMOSbackplane 2000 through the bumps 3000.

Referring to these figures, the micro-LED array display device capableof achieving full color includes a first micro-LED panel 1100, a secondmicro-LED panel 1200, and a third micro-LED panel 1300, each of whichincludes a plurality of arrayed micro-LED pixels. The first 1100, second1200, and third micro-LED panels 1300 emit light of different wavelengthbands. For example, the first, second, and third micro-LED panels 1100,1200, and 1300 may be constructed to emit red light, green light, andblue light, respectively. The micro-LED array display device capable ofachieving full color includes a single CMOS backplane 2000 adapted toindividually drive the micro-LED pixels of the first, second, and thirdmicro-LED panels 1100, 1200, and 1300. The single CMOS backplane 2000includes a plurality of CMOS cells corresponding to the micro-LED pixelsof the first, second, and third micro-LED panels 1100, 1200, and 1300.CMOS cell areas 2100, 2200, and 2300 are formed in the CMOS backplane2000 such that the micro-LED panels 1100, 1200, and 1300 are arranged onthe CMOS backplane 2000. The CMOS cell areas 2100, 2200, and 2300 areformed corresponding to the micro-LED panels 1100, 1200, and 1300,respectively. The micro-LED panels 1100, 1200, and 1300 are flip-chipbonded to the CMOS cell areas 2100, 2200, and 2300, respectively. Aplurality of CMOS cells corresponding to the micro-LED pixels of themicro-LED panels 1100, 1200, and 1300 are formed in the CMOS cell areas2100, 2200, and 2300, respectively. With this arrangement, the micro-LEDpanels 1100, 1200, and 1300 are flip-chip bonded to the single CMOSbackplane 2000 to electrically connect the micro-LED pixels to the CMOScells. The CMOS cells are electrically connected to the micro-LED pixelsthrough bumps 3000. The flip-chip bonding of the micro-LED panels 1100,1200, and 1300 to the single CMOS backplane 2000 is performed in thesame manner as that of the micro-LED panel 100 to the CMOS backplane 200explained with reference to FIGS. 1 to 4.

Common cells are formed in the CMOS cell areas 2100, 2200, and 2300 onthe single CMOS backplane 2000 and are electrically connected to firstconductivity-type metal layers of the micro-LED panels 1100, 1200, and1300 through common bumps.

As described before, the micro-LED array display device of the presentinvention in which the plurality of independently fabricated micro-LEDpanels emitting light of different wavelength bands, i.e. red, light,and blue light, are flip-chip bonded to the single CMOS backplane 2000can focus three colors on the same area using an optical system toachieve full color, thus overcoming the technical difficulties of theprior art in forming red, green, and blue light emitting structures onone substrate in the fabrication of micro-LEDs. In addition, themicro-LED array display device of the present invention can avoid theinconvenience or difficulty of wire bonding for connecting LED chips tovarious data lines, which run along the longitudinal and transverse axesand are responsible for the control of the LED chips. Furthermore, themicro-LED array display device of the present invention can eliminatethe need to dispose elements responsible for signal control in LED chipsat positions away from the LED chips, contributing to a reduction in theoverall size of the display device.

Finally, FIG. 7 is a view for briefly explaining the driving of themicro-LED array display device illustrated in FIG. 5 to achieve fullcolor. As illustrated in FIG. 7, the micro-LED array display device isdriven in response to control signals from a drive IC 700. The controlsignals from the drive IC 700 are transmitted to the micro-LED pixels bythe CMOS cells (i.e. CMOS integrated circuits) formed in the CMOSbackplane 2000. The control signals from the drive IC 700 may be analogor digital signals. The digital signals may also be pulse widthmodulation (PWM) signals.

EXPLANATION OF REFERENCE NUMERALS

100, 1100, 1200, 1300: Micro-LED panels

110: Substrate

120, 132: First conductivity-type semiconductor layers

130: Micro-LED pixel

134: Active layer

136: Second conductivity-type semiconductor layer

140: First conductivity-type metal layer

200, 2000: CMOS backplanes

230: CMOS cell

240: Common cell

340: Common bump

300, 330, 3000, 3100, 3200, 3300: Bumps

2100, 2200, 2300: CMOS cell areas

700: Drive IC

What is claimed is:
 1. A method for fabricating a micro-LED arraydisplay device comprising: preparing a micro-LED panel comprising asubstrate and a plurality of micro-LED pixels formed on the substrate bygrowing a first conductivity-type semiconductor layer, an active layer,and a second conductivity-type semiconductor layer in order on thesubstrate and removing the active layer and the second conductivity-typesemiconductor layer in predetermined portions to expose the firstconductivity-type semiconductor layer, whereby the micro-LED pixels havea vertical structure including the first conductivity-type semiconductorlayer, the active layer, and the second conductivity-type semiconductorlayer in order on the substrate and none of the micro-LED pixels isformed on the substrate in the exposed portions, wherein a firstconductivity-type metal layer is formed over a portion of the exposedportions of the first conductivity-type semiconductor layer, the firstconductivity-type metal layer being spaced apart from the micro-LEDpixels and functioning as a common electrode of the micro-LED pixels,the first conductivity-type metal layer being formed along the peripheryof the micro-LED panel on the first conductivity-type semiconductorlayer; preparing a CMOS backplane comprising a plurality of CMOS cellscorresponding to the micro-LED pixels; arranging bumps electricallyconnecting the micro-LED pixels to the corresponding CMOS cells in astate in which the micro-LED pixels are arranged to face the CMOS cells;and heating the bumps in a state in which the bumps is interposedbetween the micro-LED pixels and the CMOS cells corresponding to themicro-LED pixels.
 2. The method according to claim 1, wherein the firstconductivity-type metal layer has the same height as the micro-LEDpixels.
 3. The method according to claim 1, wherein the CMOS backplanecomprises a common cell formed at a position corresponding to the firstconductivity-type metal layer and the first conductivity-type metallayer is electrically connected to the common cell through a commonbump.
 4. The method according to claim 3, wherein the common bump isformed along the periphery of the CMOS cells on the common cell.
 5. Themethod according to claim 1, wherein the micro LED pixels areindividually flip-bonded to the CMOS cells so that the micro-LED areindividually controlled.
 6. The method according to claim 1, wherein thefirst conductivity-type is n-type and the second conductivity-type isp-type.
 7. The method according to claim 1, wherein the substrate ismade of a material selected from sapphire, SiC, Si, glass, and ZnO. 8.The method according to claim 1, wherein the step of arranging the bumpscomprises placing the substrate of the micro-LED panel having themicro-LED pixels over the CMOS backplane, so that the micro-LED pixelsformed in the substrate face the corresponding CMOS cells of the CMOSbackplane.
 9. A method for fabricating a micro-LED array display devicecomprising: preparing first, second, and third micro-LED panels emittinglight of different wavelength bands, each of the micro-LED panelscomprising a substrate and a plurality of micro-LED pixels on thesubstrate by growing a first conductivity-type semiconductor layer, anactive layer, and a second conductivity-type semiconductor layer inorder on the substrate of the corresponding first, second, and the thirdmicro-LED panels and removing the active layer and the secondconductivity-type semiconductor layer in predetermined portions toexpose the first conductivity-type semiconductor layer, whereby themicro-LED pixels of each of the first, second, and third micro-LEDpanels have a vertical structure including the first conductivity-typesemiconductor layer, the active layer, and the second conductivity-typesemiconductor layer in order on the substrate of the correspondingfirst, second, and third micro-LED panels and none of the micro-LEDpixels is formed on the substrate in the exposed portions, wherein afirst conductivity-type metal layer is formed over a portion of theexposed portions of the first conductivity-type semiconductor layer ofeach of the first, second and third micro-LED panels, the firstconductivity-type metal layer being spaced apart from the micro-LEDpixels of each of the first, second, and third micro-LED panels andfunctioning as a common electrode of the micro-LED pixels, the firstconductivity-type metal layer of each of the first, second, and thirdmicro-LED panels being formed along the periphery of each of the first,second, and third micro-LED panels on the first conductivity-typesemiconductor layer of each of the first, second, and third micro-LEDpanels; preparing a single CMOS backplane comprising a plurality of CMOScells corresponding to the micro-LED pixels; arranging bumpselectrically connecting the micro-LED pixels of the first, second, andthird micro-LED panels to the corresponding CMOS cells in a state inwhich the micro-LED pixels of the first, second, and third micro-LEDpanels are arranged to face the CMOS cells; and heating the bumps in astate in which the bumps is interposed between the micro-LED pixels andthe CMOS cells corresponding to the micro-LED pixels.
 10. The methodaccording to claim 9, wherein the first conductivity-type metal layer ofeach of the first, second, and third micro-LED panels has the sameheight as the micro-LED pixels of the first, second, and third micro-LEDpanels.
 11. The method according to claim 9, wherein the single CMOSbackplane comprises a common cell formed at a position corresponding tothe first conductivity-type metal layer of each of the first, second,and third micro-LED panels and the first conductivity-type metal layeris electrically connected to the common cell through a common bump. 12.The method according to claim 11, wherein the common bump is formedalong the periphery of the CMOS cells on the common cell.
 13. The methodaccording to claim 9, wherein the micro LED pixels are individuallyflip-bonded to the CMOS cells so that the micro-LED are individuallycontrolled.
 14. The method according to claim 9, wherein the micro-LEDdisplay device is capable of implementing full color, wherein the firstmicro-LED panel emits red color, the second micro-LED display emitsgreen color, and the third micro-LED panel emits blue color.
 15. Themethod according to claim 9, wherein the micro-LED display devicefurther comprises a drive IC, and a control signal from the drive IC issupplied to the micro-LED pixel through the corresponding CMOS cell. 16.The method according to claim 9, wherein the first conductivity-type isn-type and the second conductivity-type is p-type.
 17. The methodaccording to claim 9, wherein the substrate is made of a materialselected from sapphire, SiC, Si, glass, and ZnO.
 18. The methodaccording to claim 9, wherein the step of arranging the bumps comprisesplacing the substrate of each of the first, second, and third micro-LEDpanels having the micro-LED pixels over the CMOS backplane, so that themicro-LED pixels formed in the substrate of each of the first, second,and third micro-LED panels face the corresponding CMOS cells of the CMOSbackplane.